The invention relates to an X-ray apparatus which includes an X-ray source which is mounted on a horizontal, supporting arm. The X-ray source is movable over a patient table in a horizontal plane. The X-ray apparatus also includes an image recording device which is movable underneath the patient table in a horizontal plane. A coupling device is provided displacing both the X-ray source and the image recording device during tomography.
The coupling device consists of two parts which are telescopically movable with respect to each other and which are rotatable around a horizontal axis. One part is connected to the image recording device while the other part is detachably connected to the supporting arm.
An apparatus of this kind is known as a tomography apparatus of the type LT, made by N. V. Philips' Gloeilampenfabrieken. The coupling device thereof includes a tube, which is pivotably connected to the image recording device, and a coupling rod, which is slidable within the tube and which is detachably connected to the supporting arm. The tube is guided in a sleeve which is rotatable around a horizontal axis which extends perpendicular to the longitudinal direction of the patient table. This horizontal axis defines the sharply imaged tomography plane.
If such an X-ray apparatus is not used for making tomographs but, for example, is used for a so-called Bucky exposure, the coupling rod must be uncoupled from the supporting arm. To this end, it is necessary for the operator to walk around the apparatus and to release a pawl provided on the coupling rod in order to separate the coupling rod from the supporting arm. This requires the use of both hands.
Furthermore, U.S. Pat. No. 3,838,286 discloses an X-ray apparatus with which tomography exposures, angular exposures and so-called Bucky exposures can be made. The coupling device comprises a single rod which remains coupled to the supporting arm during angular exposures and tomography exposures. The coupling rod is slidably guided in the supporting arm for tomography exposures, while for angular exposures the coupling rod is rotatably, but not slidably, connected to the supporting arm. To this end, the coupling rod comprises ribs which are engaged by clamps connected to the supporting arm. When the coupling rod is to be uncoupled from the supporting arm, the operator again must walk around the apparatus, operate two snap mechanisms provided at the lower and the upper extremities of the coupling rod, and lift the rod from the position intended for tomography exposures or angular exposures to a storage position.